The test template scaled below 550px in all browsers. Though there are some caveats: Minimum browser widths vary, e.g. Safari 4.0 went no smaller than around 280px wide. IE6 ignores max-width (does not cap how large the image scales up to), but IE8 supports it.

If your on a mobile/email client I’ve not yet tested, let me know how it performs…

5. Alternatives

Fixed-width images:

If your using fixed images in a fluid layout, then make them small like in this KEEN mobile email:

@media query:

For devices with CSS3 support @media is an alternative. It’s supported on the iPhone, Palm and Android, though not currently under IE.

Check out Campaign Monitor’s great write up on this Panic email that uses @media. The images below are from that post:

No images:

You can always stick with a rich-text layout for your primary email, like the Good Experience newsletter. One key benefit is smaller file sizes, though I can’t see many B2C emails abandoning images altogether.

No matter what you do, some mobile devices don’t support images. Only the text is displayed like the Motorola MOTO Q below:

There’s great diversity in mobile screen sizes and varying levels of HTML support. Creating multiple, device specific email templates is impractical. We need future-proof designs that adjust to their context.

Fluid emails meet that challenge, rendering well on a PC or mobile device (not just the iPhone). But for wide adoption beyond the, “mobile version”, businesses will want the option of adding images.

Luckily, support for fluid images is stronger than I expected. I’ll certainly be doing some further testing …

While I have been able to successfully adapt to a flexible layout where the header image will flex - I seem to have problems with images I place in articles — they do not flex, even when set with the proper style. Thoughts?